I created a fluid object and a static object, connected the fluid solver to the fluid object, and merge the static object to the fluid solver, then selected the merge as collision relationship.

but the fluid object didn't occur collision to the static object, where did I wrong? Any one would make a example file?

It's strongly recommended to use the shelf tools to do straight-ahead things like this. Not only do they work very quickly, but they setup a DOPnet that does what you want - a flexible working example. Good learning tool.

I'm not in front of Houdini atm, but from memory - all from the shelf:

1. Ctl-Create Torus
2. Ctl-Liquid container
3. Size up the torus a bit because I find default unit torus tends to lose liquid too quickly.
4. Liquid From Object - select the torus, then the liquid container.
5. Ctl-Create Sphere. Move it so you'll see the water hitting it.
6. Static Object - select the sphere.
7. hit play.

You can do the same thing with a particle fluid.


Cheers,

J.C.

P.S. Btw, these [sidefx.com] are very good and worth watching.

ykcosmo
…and merge the static object to the fluid solver

This part doesn't make sense to me. Your rbdobject should be connected to a rbdsolver. Then use a merge and merge both the rbd- and the fluidsolver together. Make sure that the rbdsolver is connected first. Because by default the left input will influence the right input on the merge node.

cheers,
Daniel

edit: After re-reading your post - in case of a static object, use a static solver instead of a rbd-solver

I found my problem is the collision object is too small or too thin…..

thanks you guys